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| Titel |
Substantial carbon loss after two full crop rotations at the Gebesee agricultural site |
| VerfasserIn |
Christian Brümmer, René Dechow, Catharina Don, Annette Freibauer, Ernst-Detlef Schulze, Waldemar Ziegler, Olaf Kolle, Werner L. Kutsch |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250053468
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| Zusammenfassung |
| Since 2001 continuous eddy-covariance measurements of the CO2 exchange between
biosphere and atmosphere have been conducted at the Gebesee agricultural site. On the basis
of these data we present the net carbon (C) balance (net biome productivity, NBP) over two
full crop rotations by accounting for any additional C input or output through fertilisation or
harvest. During the nine-year observation period, winter wheat (four times) and winter barley
(once) were alternately planted with potato (twice), rapeseed (once) and sugar beet (once).
Our results show a positive NBP, i.e. a net C loss, of approximately 1 kg C m-2 from
2001-2009. This finding was confirmed by an independent soil C model, which was
calibrated with soil respiration measurements. Additionally, the soil-atmosphere exchange of
N2O and CH4 was measured from 2006-2009. We used these data to validate a newly
developed, fuzzy-logic based model to simulate the greenhouse gas (GHG) exchange
for the full observation period with the aim to calculate the total GHG balance of
the study site including all management practices. Beside the above-mentioned
significant humus loss, which is even elevated when considering N2O and CH4 (~1.7 kg
C m-2 after nine years), we found a GHG efficiency of 1 g of harvested CO2-C
equivalents against 0.5 g of management-related emissions of CO2-C equivalents. |
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